1. Field of the Invention
The present invention relates generally to an apparatus and method for controlling a dual display, and more particularly, to an apparatus and method for controlling a dual display in a mobile terminal with a projector module.
2. Description of the Related Art
In order to overcome the limitation of screen size of mobile terminals, a function capable of displaying information of the mobile terminals on large external display devices has been recently developed, such as the TV-OUT function, and the use of a connector connecting mobile terminals to the external projector devices has increased accordingly.
In addition to the above functions, a technology also has been developed that mounts a small projector module in mobile terminals instead of using the external projector devices. A mobile terminal with the projector module allows a user to view Digital Multimedia Broadcasting (DMB) images on large screens by projecting the DMB images onto any alternative screens such as A4 papers, walls and white shirts, mitigating the inconvenience of viewing the images on a small Liquid Crystal Display (LCD) screen.
When the mobile terminal includes a projector module, a user may input commands such as numbers and characters, by directly pressing buttons on a keypad of the mobile terminal in order to control the projector module. Recently, however, touch pad technology has been increasingly applied to most mobile terminals, and full-touch phones are becoming the trend of the next-generation mobile terminals. In this case, the user touches soft buttons displayed on the screen rather than pressing hard buttons on the existing keypad, and then the mobile terminal recognizes numbers, characters and commands corresponding to the touch inputs.
A full-touch LCD screen of the mobile terminal with a projector module should always be turned on in order to receive key inputs. In the conventional mobile terminal with a projector function shown in FIG. 1, for example, when a user desires to watch a DMB broadcast, an image 110 for the DMB broadcast may be projected onto a projector screen 100, and volume information, channel change information and other control command buttons may be displayed on an LCD screen 120 of the mobile terminal.
In this case, there is a need to focus on controlling the data to be output through the LCD screen 120 and the data to be output through the projector screen 100. With the development of multimedia, when large high-resolution images are processed, efficient data processing should also be considered. In images with a resolution of Wide Video Graphics Array (WVGA) (800×480 or 854×480 class), the existing Central Processing Unit (CPU) interface needs a Write Enable (WE) signal of about up to 43 nsec to transmit video data consisting of 30 frames per second to an LCD panel and a projector module. That is, if the resolution increases, the time required to display one frame should be reduced. In particular, an expensive Application Processor (AP) chip for fast signal processing is needed to avoid high power consumption.